Chrome Web Store developers can create and distribute apps and extensions that use NPAPI plug-ins. However, platforms such as ChromeOS and Windows 8 don’t support NPAPI. Today, we’re making the installation of apps and extensions that use NPAPI smarter, to help users avoid installing items that they can’t use on their particular platform.

If a user visits the Chrome Web Store on a platform that doesn’t support NPAPI, the store will filter out all items that use it from the home page and the various category pages. These apps and extensions will still show up in search results, and can be visited from direct URL links, but the Details dialog for each item will display a message that the app or the extension in question cannot be installed and the Install button will be disabled.

If you are a developer whose apps or extensions use NPAPI but can still work without it, we’ve provided a way for you to prevent your items from being filtered out. In your manifest.json file under the requirements section, specify the “npapi” flag like this:

"requirements": { "plugins": { "npapi": false } }

This will allow your apps and extensions to continue to be available to users on platforms that don’t support NPAPI. If your plug-in doesn’t have any explicit dependencies on the underlying OS, then you should really consider porting it to Native Client, which provides improved portability and security and runs just great on Windows 8 and ChromeOS.

Have any questions or comments about NPAPI? You can reach us on our developer forum for all of your store-related questions.Posted by Joe Marini, Developer Advocate